I find it surprising that with those test scores, prior experience at an elite private school, and a mother who is a G&T teacher she is finding the work challenging.

I'm wondering if there a specific skill deficit that's been unnoticed until now? But you are a teacher - you would have noticed. Does the current program emphasize something kind of obscure - so that all the kids who have been there a while are experts in it and it's new to your daughter? Or maybe she missed too much orientation at the beginning of the year and the classroom routines/procedures are overwhelming her?

If I were in your shoes I would probably micro manage her homework and studying until she regained a little confidence.

What kind of gifted program is this?